CVE-2009-5110
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · unediteddhttpd allows remote attackers to cause a denial of service (daemon outage) via partial HTTP requests, as demonstrated by Slowloris.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidencedhttpd does not implement proper timeouts or connection limits on incomplete HTTP requests, allowing attackers to send partial request headers slowly (Slowloris-style) to exhaust server resources and cause denial of service.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Authentication
- None
- Confidentiality
- None
- Integrity
- None
- Availability
- Partial
AV:N/AC:L/Au:N/C:N/I:N/A:P
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm dhttpd is installed or runningCheck for dhttpd processes or executable on the system using commands like 'ps aux | grep dhttpd' or 'which dhttpd'Affected if dhttpd process or executable is found on the system, as all versions are affected
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Check for HTTP timeout configurationInspect dhttpd configuration files for any timeout, idle-timeout, or request-timeout directivesAffected if No timeout-related configuration exists, or if timeouts are set to very high values or are not enforced
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Check for connection limit configurationInspect dhttpd configuration files for any max-connections, max-clients, or connection-limit settingsAffected if No connection limit configuration exists, or limits are set very high or are not enforced
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Test for slow header handlingSend a partial HTTP request with headers sent slowly (e.g., sending headers one at a time with delays) and observe if the connection remains open indefinitelyAffected if The connection remains open and is not terminated by the server within a reasonable timeout period (e.g., 10-30 seconds)
If dhttpd is running and does not terminate slow/incomplete HTTP connections within a short timeout period, the environment is affected by this vulnerability.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataImplement connection timeouts and maximum concurrent connection limits in the HTTP daemon, or migrate to a web server that handles partial requests properly with built-in timeout protections.
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-5110 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2009-5110 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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